fix: remove block sdt on delete press when cursor is on the first position (#3246)

* fix: remove block sdt on delete press when cursor is on the first position

* fix: return false from command for sdtLocked

Author: VladaHarbour

packages/super-editor/src/editors/v1/core/commands/core-command-map.d.ts

@@ -62,6 +62,7 @@ type CoreCommandNames =
   | 'backspaceNextToRun'
   | 'backspaceAcrossRuns'
   | 'backspaceAtomBefore'
+  | 'deleteBlockSdtAtTextBlockStart'
   | 'deleteSkipEmptyRun'
   | 'deleteNextToRun'
   | 'deleteAtomAfter'

packages/super-editor/src/editors/v1/core/commands/deleteBlockSdtAtTextBlockStart.js

@@ -0,0 +1,51 @@
+import { Selection } from 'prosemirror-state';
+
+function isSdtContentFullyLocked(node) {
+  return node.attrs.lockMode === 'sdtContentLocked';
+}
+
+function findAncestorDepth($pos, predicate) {
+  for (let depth = $pos.depth; depth > 0; depth -= 1) {
+    if (predicate($pos.node(depth))) return depth;
+  }
+  return null;
+}
+
+/**
+ * Deletes the block SDT wrapper from the start of its first paragraph.
+ *
+ * @returns {import('@core/commands/types').Command}
+ */
+export const deleteBlockSdtAtTextBlockStart =
+  () =>
+  ({ state, dispatch }) => {
+    const { selection } = state;
+    if (!selection.empty) return false;
+
+    const { $from } = selection;
+    const sdtDepth = findAncestorDepth($from, (node) => node.type.name === 'structuredContentBlock');
+    if (sdtDepth == null) return false;
+
+    const textblockDepth = findAncestorDepth($from, (node) => node.isTextblock);
+    if (textblockDepth !== sdtDepth + 1) return false;
+    if ($from.node(textblockDepth).type.name !== 'paragraph') return false;
+    if ($from.pos !== $from.start(textblockDepth)) return false;
+    if ($from.before(textblockDepth) !== $from.start(sdtDepth)) return false;
+
+    const sdtNode = $from.node(sdtDepth);
+    const lockMode = sdtNode.attrs.lockMode;
+    // Wrapper deletion is blocked for sdtLocked / sdtContentLocked (see createStructuredContentLockPlugin).
+    // For sdtLocked, content edits must still work — returning true here consumed Delete without
+    // dispatching, so the first character of the first paragraph was undeletable at this caret.
+    if (lockMode === 'sdtLocked') return false;
+    if (isSdtContentFullyLocked(sdtNode)) return true;
+
+    if (dispatch) {
+      const from = $from.before(sdtDepth);
+      const tr = state.tr.delete(from, from + sdtNode.nodeSize);
+      const selectionPos = Math.min(from, tr.doc.content.size);
+      dispatch(tr.setSelection(Selection.near(tr.doc.resolve(selectionPos), -1)).scrollIntoView());
+    }
+
+    return true;
+  };

packages/super-editor/src/editors/v1/core/commands/deleteBlockSdtAtTextBlockStart.test.js

@@ -0,0 +1,153 @@
+import { describe, it, expect, vi } from 'vitest';
+import { Schema } from 'prosemirror-model';
+import { EditorState, TextSelection } from 'prosemirror-state';
+import { deleteBlockSdtAtTextBlockStart } from './deleteBlockSdtAtTextBlockStart.js';
+
+const makeSchema = () =>
+  new Schema({
+    nodes: {
+      doc: { content: 'block+' },
+      paragraph: { group: 'block', content: 'inline*' },
+      structuredContentBlock: {
+        group: 'block',
+        content: 'block*',
+        isolating: true,
+        attrs: {
+          lockMode: { default: 'unlocked' },
+        },
+      },
+      text: { group: 'inline' },
+    },
+    marks: {},
+  });
+
+const makeDoc = (schema, lockMode = 'unlocked', sdtContent = [schema.node('paragraph', null, schema.text('Inner'))]) =>
+  schema.node('doc', null, [
+    schema.node('paragraph', null, schema.text('Before')),
+    schema.node('structuredContentBlock', { lockMode }, sdtContent),
+    schema.node('paragraph', null, schema.text('After')),
+  ]);
+
+const findBlockSdt = (doc) => {
+  let result = null;
+  doc.descendants((node, pos) => {
+    if (node.type.name === 'structuredContentBlock') {
+      result = { node, pos, end: pos + node.nodeSize };
+      return false;
+    }
+    return true;
+  });
+  return result;
+};
+
+const paragraphStartInSdt = (doc, index = 0) => {
+  const sdt = findBlockSdt(doc);
+  expect(sdt).not.toBeNull();
+
+  let seen = 0;
+  let start = null;
+  sdt.node.descendants((node, offset) => {
+    if (node.type.name !== 'paragraph') return true;
+    if (seen === index) {
+      start = sdt.pos + 1 + offset + 1;
+      return false;
+    }
+    seen += 1;
+    return true;
+  });
+
+  expect(start).not.toBeNull();
+  return start;
+};
+
+describe('deleteBlockSdtAtTextBlockStart', () => {
+  it('deletes an unlocked block SDT when the caret is at the start of its first paragraph', () => {
+    const schema = makeSchema();
+    const doc = makeDoc(schema);
+    const state = EditorState.create({ schema, doc, selection: TextSelection.create(doc, paragraphStartInSdt(doc)) });
+
+    let dispatched;
+    const ok = deleteBlockSdtAtTextBlockStart()({
+      state,
+      dispatch: (tr) => {
+        dispatched = tr;
+      },
+    });
+
+    expect(ok).toBe(true);
+    expect(dispatched).toBeDefined();
+    expect(findBlockSdt(dispatched.doc)).toBeNull();
+    expect(dispatched.doc.textContent).toBe('BeforeAfter');
+  });
+
+  it('returns false for sdtLocked so Delete can fall through for in-SDT content edits', () => {
+    const schema = makeSchema();
+    const doc = makeDoc(schema, 'sdtLocked');
+    const state = EditorState.create({ schema, doc, selection: TextSelection.create(doc, paragraphStartInSdt(doc)) });
+    const dispatch = vi.fn();
+
+    const ok = deleteBlockSdtAtTextBlockStart()({ state, dispatch });
+
+    expect(ok).toBe(false);
+    expect(dispatch).not.toHaveBeenCalled();
+  });
+
+  it('consumes sdtContentLocked block SDT wrapper delete without dispatching', () => {
+    const schema = makeSchema();
+    const doc = makeDoc(schema, 'sdtContentLocked');
+    const state = EditorState.create({ schema, doc, selection: TextSelection.create(doc, paragraphStartInSdt(doc)) });
+    const dispatch = vi.fn();
+
+    const ok = deleteBlockSdtAtTextBlockStart()({ state, dispatch });
+
+    expect(ok).toBe(true);
+    expect(dispatch).not.toHaveBeenCalled();
+  });
+
+  it('returns false when the caret is not at the paragraph start', () => {
+    const schema = makeSchema();
+    const doc = makeDoc(schema);
+    const state = EditorState.create({
+      schema,
+      doc,
+      selection: TextSelection.create(doc, paragraphStartInSdt(doc) + 1),
+    });
+    const dispatch = vi.fn();
+
+    const ok = deleteBlockSdtAtTextBlockStart()({ state, dispatch });
+
+    expect(ok).toBe(false);
+    expect(dispatch).not.toHaveBeenCalled();
+  });
+
+  it('returns false from later paragraphs inside the same block SDT', () => {
+    const schema = makeSchema();
+    const doc = makeDoc(schema, 'unlocked', [
+      schema.node('paragraph', null, schema.text('First')),
+      schema.node('paragraph', null, schema.text('Second')),
+    ]);
+    const state = EditorState.create({
+      schema,
+      doc,
+      selection: TextSelection.create(doc, paragraphStartInSdt(doc, 1)),
+    });
+    const dispatch = vi.fn();
+
+    const ok = deleteBlockSdtAtTextBlockStart()({ state, dispatch });
+
+    expect(ok).toBe(false);
+    expect(dispatch).not.toHaveBeenCalled();
+  });
+
+  it('returns false outside a block SDT', () => {
+    const schema = makeSchema();
+    const doc = makeDoc(schema);
+    const state = EditorState.create({ schema, doc, selection: TextSelection.create(doc, 1) });
+    const dispatch = vi.fn();
+
+    const ok = deleteBlockSdtAtTextBlockStart()({ state, dispatch });
+
+    expect(ok).toBe(false);
+    expect(dispatch).not.toHaveBeenCalled();
+  });
+});

packages/super-editor/src/editors/v1/core/commands/index.js

@@ -52,6 +52,7 @@ export * from './backspaceSkipEmptyRun.js';
 export * from './backspaceNextToRun.js';
 export * from './backspaceAcrossRuns.js';
 export * from './backspaceAtomBefore.js';
+export * from './deleteBlockSdtAtTextBlockStart.js';
 export * from './deleteSkipEmptyRun.js';
 export * from './deleteNextToRun.js';
 export * from './deleteAtomAfter.js';

packages/super-editor/src/editors/v1/core/extensions/keymap.js

@@ -37,6 +37,7 @@ export const handleBackspace = (editor) => {
       tr.setMeta('inputType', 'deleteContentBackward');
       return false;
     },
+    () => commands.deleteBlockSdtAtTextBlockStart(),
     () => commands.backspaceEmptyRunParagraph(),
     () => commands.backspaceSkipEmptyRun(),
     () => commands.backspaceAtomBefore(),
@@ -55,6 +56,7 @@ export const handleDelete = (editor) => {
   dispatchHistoryBoundary(view);
 
   return editor.commands.first(({ commands }) => [
+    () => commands.deleteBlockSdtAtTextBlockStart(),
     () => commands.deleteSkipEmptyRun(),
     () => commands.deleteAtomAfter(),
     () => commands.deleteNextToRun(),